[ʌɪˈdiːəlɪz(ə)m], (Noun)

Definitions:
- the unrealistic belief in or pursuit of perfection
(e.g: the idealism of youth)

- any of various systems of thought in which the objects of knowledge are held to be in some way dependent on the activity of mind


Phrases:

Origin:
mid 18th century (in idealism): from ideal + -ism, after French idéalisme or German Idealismus